FRI

FRI API Overview

Structs

FriTranscriptConfig

Configuration structure for the FRI protocol's transcript.

Fields:

• hash: &Hasher - Reference to the hashing function used.
• domain_separator_label: String - Domain separator label for transcript uniqueness.
• round_challenge_label: String - Label for the challenge at each round.
• commit_phase_label: String - Label for the commit phase.
• nonce_label: String - Label for the nonce.
• public_state: Vec<u8> - Public state data.
• seed_rng: F - The seed for initializing the RNG.

Methods:

• new(hash, domain_separator_label, round_challenge_label, commit_phase_label, nonce_label, public_state, seed_rng) -> Self: Constructs a new FriTranscriptConfig with explicit parameters.

• new_default_labels(hash, seed_rng) -> Self: Constructs a FriTranscriptConfig with default labels.

FFIFriTranscriptConfig

FFI configuration structure for the FRI protocol's transcript.

• Conversion from FriTranscriptConfig using From trait.

FriProof

A structure representing the FRI proof, which includes methods for handling proof data.

Methods:

• new() -> Result<Self, eIcicleError>: Constructs a new instance of the FriProof.

• create_with_arguments(query_proofs_data, final_poly, pow_nonce) -> Result<Self, eIcicleError>: Creates a new instance of FriProof with the given proof data.

• get_query_proofs(&self) -> Result<Vec<Vec<MerkleProofData<F>>>, eIcicleError>: Returns the matrix of Merkle proofs, where each row corresponds to a query and each column corresponds to a round.

• get_final_poly(&self) -> Result<Vec<F>, eIcicleError>: Returns the final polynomial values.

• get_pow_nonce(&self) -> Result<u64, eIcicleError>: Returns the proof-of-work nonce.

FriConfig

Configuration structure for the FRI protocol.

Fields:

• stream_handle: IcicleStreamHandle - Stream for asynchronous execution.
• folding_factor: u64 - The factor by which the codeword is folded in each round.
• stopping_degree: u64 - The minimal polynomial degree at which folding stops.
• pow_bits: u64 - Number of leading zeros required for proof-of-work.
• nof_queries: u64 - Number of queries, computed for each folded layer of FRI.
• are_inputs_on_device: bool - True if inputs reside on the device (e.g., GPU).
• is_async: bool - True to run operations asynchronously.
• ext: ConfigExtension - Pointer to backend-specific configuration extensions.

Methods:

• default() -> Self: Returns a default FriConfig instance with standard settings.

Example Usage

Below is an example demonstrating how to use the fri module:

let merkle_tree_leaves_hash = Keccak256::new(std::mem::size_of::<ScalarField>() as u64).unwrap();
let merkle_tree_compress_hash = Keccak256::new(2 * merkle_tree_leaves_hash.output_size()).unwrap();
let transcript_hash = Keccak256::new(0).unwrap();

const SIZE: u64 = 1 << 10;

init_domain::<ScalarField>(SIZE, false);

let fri_config = FriConfig::default();
let scalars = ScalarCfg::generate_random(SIZE as usize);
let transcript_config = FriTranscriptConfig::new_default_labels(&transcript_hash, ScalarField::one());
let merkle_tree_min_layer_to_store = 0;

let fri_proof = fri_merkle_tree_prove::<ScalarField>(
    &fri_config,
    &transcript_config,
    HostSlice::from_slice(&scalars),
    &merkle_tree_leaves_hash,
    &merkle_tree_compress_hash,
    merkle_tree_min_layer_to_store,
)
.unwrap();

let valid = fri_merkle_tree_verify::<ScalarField>(
    &fri_config,
    &transcript_config,
    &fri_proof,
    &merkle_tree_leaves_hash,
    &merkle_tree_compress_hash,
)
.unwrap();

assert!(valid);

Links

For more information on FRI concepts, see FRI Primitives.